Self-cleaning textile motor



May 28, 1940. J. L. BROWN SELF-CLEANING TEXTILE MOTOR Filed Dec. 23, 1937 J0]??? LB/"awn.

ATTORNEY Patented May 28, 1940 r.

2,202,622 SELF-CLEANING TEXTILE Moron John L. Brown, Verona, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application December 23, 1937, Serial No. 181,340

5 Claims.

The present invention relates to the frame construction of dynamo-electric machines and more specifically to motors designed for textile mill service.

In textile mills, the air is usually more or less filled with lint, which is a light, flufly material easily blown around by currents of air and considerable trouble is experienced with electric motors used in such mills due to clogging of the dangerous since the lint is rather inflammable and it is, therefore, necessary for the motor to be cleaned out from time to time. With many conventional designs of motors, this requires removal of the end brackets causing considerable diiliculty and loss of time.

The object of the present invention is to provide a motor for textile mill service which will be self-cleaning in that lint carried into the machine by the ventilating air will pass on through and not lodge in the machine.

A further object is to provide a frame construction which will permit the motor to be easily cleaned out, if necessary, without the removal of the end bells or other disassembly.

These objects are attained by using a frame construction in which the usual end rings are omitted and the end bells or brackets are supported on axially extending projections or supporting members formed on a central ring-shaped frame member so that large openings are left on either side between the end bells and frame member for the escape of ventilating air. The interior of the end bells affords a smooth and unbroken surface having no projections or other points on which thelint can lodge and it is therefore carried through the machine by the ventilating air and does not clog the air passages. If it should become necessary to clean out the motor, however, it can be easily done by inserting an air hose into the openings between the frame member and end bells and blowing out any lint or other material that may have accumulated.

The space between the end bells and the frame member is made large enough to permit the flow .01 a sufficient-volume of air at high enough velocity to provide proper cooling of the motor but in every case it will be wide enough to provide a large, unobstructed opening which will permit the lint to be carried out by the air without any possibility of its being caught and clogging the air outlet. The shape of the frame member is such that it provides sloping outer surfaces and the diameter of the end bells at their inner edges is greater than the inner diameter of the frame member so that they extend past it in the radial direction and the inner surfaces of the end bells cooperate with the outer surfaces of the frame member to form smooth, unobstructed air outlets which offer no points of attachment for lint. The supporting members for the end bells are made as small and as few in number as considerations of mechanical strength will permit and are rounded and tapered to offer as little resistance as possible to the flow of air and to insure that no lint will be caught on them.

The invention will be more fully understood from the following detailed description, taken in connection with the accompanying drawing, in which Figure l is a perspective view of the motor;

Fig. 2 is a view partly in side elevation and partly in longitudinal section; and

Fig. 3 is a detailed view of the upper part of the frame showing an alternative construction.

As shown in Figs. 1 and 2, the motor has a central ring-shaped frame member i having a generally triangular cross section, and a stator core 2, having windings 3 placed in slots therein. The stator core may be of any suitable construction but any radial air ducts are preferably omitted. The frame member I is bored to fit the outside of the stator core 2 which is supported directly on the frame. Downwardly extending bosses 4 are formed on the frame member I and foot supports5 are secured to these bosses in any desired manner. Holes- 6 for the reception of mounting bolts are provided in the foot supports 5. A plurality of axial projections I which serve as supporting members for the end bells are formed on the exterior of the frame member i and extend generally parallel to its axis. projections taper towards their ends as indicated at 8 in Fig. 2, and are rounded in cross section as shown at 9.

End bells indicated generally at ID are provided at each end of the machine and are secured to the supporting members 1 by cap screws II or other suitable fastening means. These end bells have central openings l2 for the entrance of These.

iii

air and smooth, uninterrupted, generally bellshaped interior surfaces l3. Bearing units ll are supported on ribs IS on the end bell and a shaft 16 is supported for rotation in the bearings. A rotor member I! of any suitable construction is keyed or otherwise secured to the shaft "5 and has fan blades 18 secured to its ends. It will be seen that the end bells are supported by the projections l in axially spaced relation to the frame member I and that their inner diameter is greater than the inner diameter of the frame member so that large, unobstructed openings are formed between the sloping outer surfaces of the frame member and the inner edges of the end bells. These edges are formed with shoulders i9 which fitover the ends of the projections i so that these ends do not extend into the path of the air where they would provide points of lodgement for the lint. The frame member i has been described as having a generally triangular cross-section, but it will be apparent that other shapes could be used, such as trapezoidal or semielliptical, which will provide oppositely sloping upper surfaces to cooperate with the end bells in forming unobstructed openings for the escape of air and the term generally triangular" is to be understood as including these shapes.

In operation, air is drawn into the machine by the action of the fan blades it and enters through the openings l2. The air passes around the stator windings 3 in a curved path and escapes from the machine through the openings between the inner edges of the end bells and the outer surfaces of the frame member 6. Lint carried by this air is thrown against the inner surface of the end bell and is carried along this surface by the flow of air. Since this is smooth and unbroken, there is no point of attachment at which the lint can lodge and it is, therefore, carried out of the machine with the air, thus preventing any clogging of the air passages. The stator core preferably has no radial air ducts in which lint could accumulate and therefore it may be supported directly on the interior of the frame member I. The heat produced in the core and that communicated to it from the stator windings 3 flows directly into the frame member l and, since the outer surfaces of this member form part of r the air outlets, the heat is rapidly dissipated by the flow of air over these surfaces.

The shape of the openings between the frame member and the end bells is such that an air hose can be readily inserted in them in order to clean out the motor when necessary. The air hose can be inserted as far as the ends of the stator windings and the air striking the interior surface of the end bell is deflected back under the stator windings so that all parts of the machine are reached by the stream of air to blow out any lint or other foreign matter that may have accumulated in the motor.

Fig. 3 shows an alternative construction in which end rings are provided on the frame mem-.

ber. This figure shows the upper part of a frame member 20 similar to the frame member I, pre- .,viously described, and having axial supporting members 2| thereon, similar in construction to the supporting members .1 described above. In this embodiment of the invention, however, end rings 22 are cast integral with the supporting members and the end bells 23 are secured to these end rings in any desired manner. The end bells 23 are preferably similar to the end bell H) described above. The joint 24 between the end bell and the end ring is carefully machined to provide a smooth surface so that there is no point of attachment for the lint carried through the machine.

The embodiment illustrated in Figs. 1 and 2 is the preferred form of the invention, since, with the construction of Fig. 3, the cost of casting the frame will be higher because of the end rings which are integral with it and the cost of the motor will also be increased by the extra machining required to make sufficiently smooth joints between the end rings and the end bells. It is also difficult to keep this joint smooth throughout the life of the motor, especially if it becomes necessary to remove the end bells. It will be seen, however, that with either construction, a motor has been provided for service in textile mills which will be free of the troubles caused by lint clogging the air passages and will be self-cleaning in that the lint will pass through it without being caught and the air spaces in the motor will be maintained open for free circulation of air. It will also be apparent that the usefulness of this motor is not limited to textile mill installations, but that it may be used to advantage in any location where the air is filled with particles of light material which may be carried into the motor with the ventilating air and caught therein.

Although two specific embodiments of the invention have been illustrated and described, it is to be understood that it is capable of various modifications and embodiments and, therefore, is not limited to the particular construction shown, but, in its broadest aspect, it includes all equivalent embodiments which come within the scope of the appended claims.

I claim as my invention:

1. A dynamo-electric machine having a central ring-shaped frame member of generally triangular cross-section, a stator core supported in said frame member, a plurality of rounded, tapered projections extending axially from said frame member, end bells having openings for the entrance of ventilating air and smooth, uninterrupted interior surfaces, said end bells having greater diameters at their inner edges than the inner diameter of the frame member and being supported on said projections in spaced relation to the frame member to provide large, unobstructed openings for the escape of air between the outer surfaces of the frame member and the adjacent edges of the end bells.

2. A dynamo-electric machine having a central ring-shaped frame member of generally triangular cross section, a stator core supported directly on said frame member, a plurality of rounded, tapered projections extending axially from said frame member, end bells having openings for the entrance of ventilating air and smooth, uninterrupted interior surfaces, said end bells having greater diameters at their inner edges than the inner diameter of the frame member and being supported on the ends of said projections in spaced relation to the frame member to provide large, unobstructed openings for the escape of air between the outer surface of the frame member and the adjacent edges of the end bells.

3. A dynamo-electric machine having a central ring-shaped frame member of generally triangular cross-section, a stator core supported in the frame member, a plurality of projections on the frame member extending axially on both sides thereof, end rings on the ends of the projections, said end rings being spaced axially from the frame member and being of greater diameter than the inner diameter of the frame member to provide large, unobstructed openings for the escape of ventilating air between the end rings and the surfaces of the frame member, and end bells secured to the end rings, said end bells'having openings for the entrance of air and having smooth, continuously curved interior surfaces.

4. A dynamo-electric machine having a central ring-shaped frame .member, supporting means for the machine on said frame member, a stator core supported directly in the frame member, said frame member having a plurality of projections extending therefrom axially of the machine, said projections being relatively wide and of relatively large cross-section to give them mechanical strength and rigidity and having smooth surfaces, and end bells having openings for the entrance of ventilating air and smooth, uninterrupted interior surfaces, the diameter of said end bells at their inner edges being greater than the inside diameter of the frame member, said end bells being supported solely on said projections and being spaced from the frame member by the projections at all points around the circumference of the frame member.

5. A dynamo-electric machine having a central ring-shaped frame member, supporting means for the machine on said frame member, a stator core supported directly in the frame member, said frame member having a plurality of projections extending therefrom axially of the machine, said projections being relatively wide and of relatively large cross-section to give them mechanical strength and rigidity and having smooth sur faces, and end bells having openings for the entrance of ventilating air and smooth, uninterrupted interior surfaces, said end bells extending radially beyond the frame member and being supported solely on said projections, the projections spacing the end bells from the frame member at all points around the circumference of the frame member.

JOHN L. BROWN. 

